RESUMO
Objective To prepare PLGA/PEG microsphcres for sustained release of bovine serum albumin (BSA), and evaluate the effect of the micrnsphere composition, proportion of the components and integration of PEG on the size, BSA encapsulation rate and in vitro BSA release properties of the microspheres. Methods BSA-loaded PLGA/PEG microspheres were prepared by water-in-oil-in-water double emulsions-solvent evaporation method (W/O/W). The morphology of the microspheres was observed with scanning elect'on microscope, the diameter was determined by Mastersizer 2000, and the encapsulation efficiency and in vitro BSA release were evaluated by UV spectrophotometry. Results Increased GA to LA ratio was associated with increased size of the microspheres and accelerated BSA release. The incorporation of PEG obviously increased the BSA encapsulation rate to as much as 88.22% with also increased BSA release rate. The BSA-PLGA/PEG biodegradable microspheres prepared was characterized by high encapsulation rate, low burst release, and slow BSA release for over 3 weeks at high drug concentrations. Conclusion BSA-PLGA/PEG microspheres with relatively high encapsulation efficiency and proper drug loading can be prepared by adjusting the parameters during the preparation process.